Voltage surge arresters of the type used for protecting electrical equipment from damaging voltage surges generally include a plurality of series gap devices to interrupt the power system follow current through the arresters. Spark gap assemblies are described in U.S. Pat. No. 3,619,708 and 3,524,099 and both of these patents are incorporated herein by way of reference.
The gap assemblies, within the aforementioned U.S. patents, not only serve to provide an open circuit to the lightning arresters in quiescent conditions but also serve to extinguish the arc which occurs when the arresters are caused to operate due to an overvoltage. One efficient method for rapidly extinguishing the arc which occurs is by magnetically directing the arc into contact with the insulating structure supporting the gap electrodes. The supporting structure may consist of a sintered porous aluminum oxide disc which serves to electrically insulate and set the gap electrode spacing and also to quench the arc. When the arc is forced into contact and permeates the aluminum oxide surfaces the arc becomes thermally cooled and rapidly loses energy. By forcing the arc to contact a plurality of the aluminum oxide surfaces the arc rapidly becomes extinguished.
With the continued rising cost of electrical power transmission and distribution, means are currently being investigated for reducing the cost and increasing the efficiency of the materials and the designs used.
The purpose of this invention is to provide an efficient surge arrester gap assembly at a substantial reduction in size and materials cost.